Rotary cutting device with quick-release blades

ABSTRACT

A rotary cutting device or element ( 20 ) includes a base or support housing ( 30 ) with a centrally arranged fastening region ( 32 ) adapted to operatively connect with an associated drive ( 24 ) that rotates the element ( 20 ) about a first rotational axis ( 44 ). The support housing ( 30 ) further includes an outer edge or periphery ( 50 ) disposed away from the centrally arranged fastening region ( 32 ). At least one cutting tool ( 22 ), including a proximate end ( 52 ), is selectively attachable to the support housing ( 30 ) at the outer edge or periphery ( 50 ) thereof. Preferably, a spring biased retaining member ( 72 ) is engaged with the proximate end ( 52 ) of the cutting tool ( 22 ) to thereby secure the same to the support housing ( 30 ).

BACKGROUND OF THE INVENTION

[0001] The present invention relates to the horticultural and/or lawncare arts. It is especially relevant to the selective cutting, trimming,or removal of unwanted weeds, overgrown grasses, and other vegetation orplants. It finds particular application in connection with powertrimmers or weed whackers, and will be described with particularreference thereto. However, it is to be appreciated that the presentinvention is also amenable to other like applications which employ arotary cutting tool or device, e.g., lawn mowers, brush choppers andother landscaping and gardening equipment.

[0002] In the horticultural and/or lawn maintenance fields, a wide rangeof power-driven equipment for cutting or trimming unwanted growth isemployed. For large area cutting such as for mowing lawns or fields,equipment such as, riding mowers, push or self-driven power mowers,brush choppers and the like, are commonly employed. This type ofequipment is often wheel based such that it supported by and rollsacross the area to be cut. It typically includes one or more rotatingcutting tools (e.g., a sharpened blade of steel, or another hard metal)powered by a combustion engine, an electric motor, or another type ofdrive. The rotating cutting tool in much of this type of equipment isposition at a selected height substantially horizontal to the surface ofthe area being cut. As the equipment traverses the area, e.g., on itswheels, the underlying grass or other vegetation is cut at a uniformheight corresponding to the separation of the rotating cutting tool fromthe ground.

[0003] One piece of equipment, which is typically a hand-held and/orhand-operated power-driven cutting or trimming device, is known in theart as a power trimmer or weed whacker. Power trimmers are commonly usedfor selectively cutting or trimming unwanted vegetation in places orregions unsuited and/or inhospitable to the aforementioned large areacutting equipment, e.g., at lawn edges; near garden beds; around fences,trees or other obstacles; in tight or confined areas where largerequipment will not readily fit; in other areas where artificial fixturesor plants such as flowers or vegetables are desirably left unscathed; onuneven or heavily sloped terrain which is difficult to negotiated byequipment which rests on the ground; etc. In a typical embodiment, aweed whacker includes an elongated shaft having a handle or other gripdisposed at a first end, and a rotary cutting element or device disposedat an opposite cutting end. A drive, such as a combustion engine, anelectric motor or otherwise, is often arranged on the weed whacker topower the rotating cutting element via a drive shaft or other linkage.

[0004] In operation, a user holds the weed whacker by the handle or gripend (i.e., the operating end) and guides the cutting end into theovergrown grass, weeds, or other unwanted plant growth which is to betrimmed or cut. In a typical embodiment, the rotating cutting elementincludes a cutting tool which rotates rapidly under the influence of theoperating motor and which strikes and cuts the targeted plant stems,branches, leaves, etc., in a rapid cutting motion which minimizes damageto the remaining uncut portion of the targeted plant. Optionally, theoperating end also includes a trigger or other switch for selectivelyengaging the rotary cutting device or element, a throttle lever forcontrolling engine speed, and similar or other operating controls.

[0005] In some known power trimmer or weed whacker embodiments, thecutting tool is a blade made of steel or other hard material which isintegrally attached to the rotating cutting element and radially extendsoutward therefrom. A blade has advantages in cutting strength and indurability. However, the blade edge wears down over time. When the bladeedge becomes sufficiently dulled, it has to be re-sharpened or replaced.Due to its integral construction, replacement typically involves areplacement of the entire rotating cutting element or device. Sharpeningalso typically involves removal of the whole rotary cutting element. Ineither case, the detachment can involve tools such as a wrench which maynot be readily available in the field. Detachment of the rotatingcutting element can also be complicated by corrosion of the bolt orother fastener which secures it to the trimmer, e.g., due to extendedexposure of the rotating cutting element to moisture and othercontaminants. In any event, the removal of the entire rotary cuttingdevice can be an inefficient and disadvantageously time consumingprocess. For commercial users especially, in addition to being a bother,the time expended in such efforts is lost time with respect to gettingjobs completed. With heavy use, this lost time can add up quickly.Additionally, the “in service” to “down time” ratio for the trimmer isdisadvantageously impacted to the extent maintenance time is increasedby such inefficiencies.

[0006] Blade damage can be accelerated by inadvertent impacts withrocks, tree trunks, and other hard object. Such impacts can cause acatastrophic blade fracture or other failure. Because the cutting end ismanually guided, such impacts are to be expected at least occasionally.The difficulty and expense in re-sharpening or replacing the bladetypically dictates using a very hard, durable blade material such assteel. However, although any manually guided rotating cutting elementpresents a safety hazard, a rigidly attached steel blade can beespecially dangerous. The steel blade is relatively inflexible andcannot bend around or flex to avoid or lessen the full impact withobjects inadvertently struck. The inflexibility combined with the bladehardness tends to result in substantial injury or damage to the struckobject or the blade.

[0007] In part, to avoid some of the aforementioned difficulties, inother known weed whacker embodiments the cutting tool is a length ofnylon string or similarly tough but flexible material connected to therotary cutting element. Under rapid rotation, an end of the nylon stringis drawn radially out and away from the axis of rotation by centrifugalforce to form an elongated whip suitable for the cutting tasks. In atypical arrangement, the rotating cutting element includes a reel ofnylon thread which is selectively unreeled, e.g., in a stepped fashion,to provide a controlled length for cutting and/or replace length as thenylon thread disintegrates or otherwise shortens due to wear.

[0008] Flexible elongated elements such as nylon thread can bend aroundor flex to avoid or lessen the impact with an object, and can thereforebe safer than a rigidly attached inflexible blade. However, the highlyabrasive cutting can quickly disintegrate the comparatively soft nylonstring, requiring inconvenient repeated operation of the unreelingmechanism to maintain a usable length. When all the string on the reelis used up, it typically has to be replaced. Hence, the samedisadvantages previously described with respect to the integral bladecutting tool are encountered. Both the unreeling mechanism and the reelreplacement can be complicated by grass clippings and other contaminantswhich can jam up the unreeling mechanism. Furthermore, the bending andflexing of the flexible string which beneficially improves safety alsosubstantially limits cutting strength, so that nylon string weedwhackers are usually limited in application to light duty cutting tasks.Further, the nylon string can tend to be come tangled which in turndemands further maintenance.

[0009] The present invention contemplates a new and improved rotarycutting device with quick-release blades and/or an associated methodthat overcomes the above-mentioned limitations and others.

BRIEF SUMMARY OF THE INVENTION

[0010] In accordance with one embodiment of the present invention, arotary cutting device is provided. The rotary cutting device includesbase having: a coupling region adapted for connection of the base withan associated drive that rotates the base; a slot at a periphery of thebase; and, a hollow shaft in communication with the slot. A retainingmember arranged in the hollow shaft is movable between a first positionwherein the retaining member intersects the slot and a second positionwherein the retaining member does not intersect the slot. A cutting toolhas a proximate end and a cutting region extending therefrom. Theproximate end is arranged to be received in the slot and has an openingarranged to receive the retaining member therethrough when the retainingmember is in the first position.

[0011] In accordance with another embodiment of the present invention, ahorticultural apparatus includes a drive and a base operativelyconnected to the drive for selective rotation thereby. The base has aperipheral opening, and a cutting tool having a proximate end isreceived into the peripheral opening. A retaining member is arranged inthe base. The retaining member is movable between a first position inwhich the retaining member is engaged with the cutting tool to securethe cutting tool to the base and a second position in which theretaining member is disengaged from the cutting tool to release thecutting tool from the base.

[0012] In accordance with yet another embodiment of the presentinvention, a rotary cutting element is provided to which a cutting toolis selectively secured. The rotary cutting element has a centrallyarranged fastening region adapted to operatively connect with a drivethat rotates the rotary cutting element, and a periphery having a slotadapted to receive an end the cutting tool. A recess is in communicationwith the slot, and a retaining member arranged in the recess. Theretaining member is slidable between a first position wherein theretaining member intersect the slot and a second position wherein theretaining member does not intersect the slot. A spring biases theretaining member toward the first position.

[0013] One advantage of the present invention resides in the capabilityto provide for quick and easy cutting tool attachment to and/ordetachment from a rotary cutting device or element.

[0014] Another advantage of the present invention resides in thecapability to remove and/or secure cutting tools to a rotary cuttingdevice in the field without resort to tools such as a wrench or thelike.

[0015] Yet another advantage of the present invention resides in thecapability to lower the down time for horticultural equipment byincreasing the ease and speed at which cutting tool maintenance and/orreplacement can be carried out.

[0016] Numerous additional advantages and benefits of the presentinvention will become apparent to those of ordinary skill in the artupon reading and understanding the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The invention may take form in various components andarrangements of components, and in various steps and arrangements ofsteps. The drawings are only for purposes of illustrating the preferredembodiments and are not to be construed as limiting the invention.

[0018]FIG. 1 shows an exemplary power trimmer in accordance with aspectsof the present invention.

[0019]FIG. 2 shows a partially cut-away perspective view of the rotarycutting device shown in FIG. 1 with the cutting tools removed and withone retention assembly removed.

[0020]FIG. 3 shows a cross-sectional view of the rotary cutting deviceshown in FIG. 1 with the cutting tools and the retention assembliesremoved.

[0021]FIG. 4 shows an exploded cross-sectional view of the rotarycutting device shown in FIG. 1 with the cutting tools removed.

[0022]FIG. 5A shows a top view of one of the cutting tools shown in FIG.1.

[0023]FIG. 5B shows a side view of one of the cutting tools shown inFIG. 1.

[0024]FIG. 6 shows a partial cross-sectional view of the rotary cuttingdevice shown in FIG. 1 with an installed cutting tool, and also shows aninstrument/key suitable for use in selectively removing and installingthe cutting tools.

[0025]FIG. 7 shows a power mower employing a rotary cutting device orelement (shown in phantom) in accordance with aspects of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

[0026] With reference to FIG. 1, a weed whacker or power trimmer 10includes an elongated shaft or supporting member 12 connecting a firstoperating end 14 and an opposing second cutting end 18. At the firstoperating end 14, a handle or grip 16 is arranged for manually holding,operating and/or guiding the trimmer 10. At the second cutting end 18, arotary cutting device or element 20 includes one or more cutting tools22 that rotate about responsive to a rotation of the cutting element 20.

[0027] Preferably, the trimmer 10 also includes a drive 24, such as acombustion engine, an electric motor or otherwise, that selectivelypowers the trimmer 10. In response to a user's manipulation of anoperating control 28, such as a trigger, on/off button, etc., the drive24 effects rotation of the rotary cutting device or element 20, e.g.,via a drive shaft 26 or other linkage operatively connected with therotating cutting element 20.

[0028] With added reference to FIGS. 2-4, in a suitable embodiment, therotating cutting element 20 includes a base or support housing 30optionally formed of two mating pieces 30 a, 30 b which are rigidlyconnected to one another by one or more screws, bolt/nut combinations,clamps, adhesive, or other fasteners (not shown). The support housing 30has a centrally arranged fastening region 32 for attaching the cuttingelement 20 to the drive shaft 26 or other suitable rotating drivemember. As shown, the fastening region 32 includes a central opening 34in the first or bottom housing piece 30 a, and a central opening 38 inthe second or top housing piece 30 b.

[0029] Preferably, an adaptor 36 is configured to receive a connectingbolt 40 or other fastening portion or connecting end of the drive shaft26. The adaptor 36 suitably includes a washer having an outer diameterconforming with the opening 38 arranged in the second housing piece 30b. As shown, the opening 38 cooperates with the first housing piece 30 ato create an annular recess about the central opening 34 for receivingthe washer 36. The inner diameter of the adaptor 36 is sized to match anouter diameter of the drive shaft 26 or a tip connecting portionthereof. Optionally, a plurality of different-sized adaptors 36 areavailable. In this manner, the assortment of adaptors 36 with differentinner diameters allow the same cutting element 20 to be tailored forconnection to and/or use with a variety of trimmers having differentdiameter connecting ends.

[0030] In the illustrated embodiment, a nut 42 cooperating with thethreaded portion or bolt 40 at the shaft tip secures the cutting element20 to the shaft 26 via the fastening region 32. However, other fastenerscan be employed. In this manner, the secured rotating cutting element 20is affixed to the shaft 26 and rotates about a rotational axis 44responsive to the rotation of the drive shaft 26.

[0031] With added reference to FIGS. 5A and 5B and FIG. 6, in onesuitable embodiment, a plurality of the cutting tools 22 (preferably 3to 5, more preferably 4) are arranged about a periphery or outer edge 50of the support housing 30. The outer edge 50 is arranged distally fromthe central fastening region 32. As the support housing 30 is rotatedabout the first rotational axis 44 the outer edge 50 experiences acentrifugal force directed radially outward from the rotational axis 44.

[0032] Preferably, each cutting tool 22 includes: a substantially flatmember at a proximate end 52 with an opening 54 therein adapted forrotatable attachment of the cutting tool 22 to the outer edge 50 of thesupport housing 30; and, a cutting region 56 extending outwardly fromthe proximate end 52 and being adapted for cutting or trimmingvegetation. In the illustrated embodiment, the cutting region 56 is anextension of the substantially flat member at the proximate end 52,having sharpened edges to form a blade. While a particular blade shapeis shown in FIG. 5A, it is to be appreciated that other shapes are alsocontemplated, such as a scythe or crescent, a rectangle, a triangle,etc. Further, while a blade is illustrated, it is to be appreciated thatthe cutting tool 22 may also use some other type of cutting device,e.g., the cutting region 56 may constitute a whip attached to thesubstantially flat member at the proximate end 52.

[0033] In the illustrated embodiment, the periphery edge 50 includes anannular slot 60 defined by a separation of the housing pieces 30 a, 30 bat the edge 50. The slot 60 defines a plane 62 (indicated by a dashedline in FIGS. 3 and 6) which is substantially perpendicular to therotational axis 44. Spaced about the circumference, the periphery regionalso includes a plurality of cylindrical or otherwise shaped hollowshafts or recesses 64 (see, e.g. FIG. 2) corresponding in number to theplurality of cutting tools 22. An axis 66 of each recess 64 defines asecond rotational axis which is substantially parallel to the first axisof rotation 44 but radially displaced therefrom, and which is alsosubstantially perpendicular to the plane 62. Each recess 64 includes afirst recess portion 64 a formed into the first housing piece 30 a, anda second recess portion 64 b formed into the second housing piece 30 b.As shown, the recess portion 64 b is deeper than the recess portion 64a. The recess portions 64 a, 64 b meet at the slot 60 so that whencombined the cylindrical recess 64 intersects the slot 60. Furthermore,openings 68 are included in the first housing piece 30 a whichcorrespond to the recess portions 64 a and communicate therewith. Theopenings 68 preferably include a smaller diameter than the recessportion 64 a.

[0034] A retention assembly 70 cooperates with the opening 54 of theproximate end 52 of the cutting tool 22 to rotatably retain theproximate end 52 of the cutting tool 22 in the slot 60. In a suitableembodiment, a retaining member or shaft 72 and a biasing spring 74 arearranged in each recess 64 as shown. Optionally, as shown, e.g., inFIGS. 4 and 6 in phantom, the shaft 72 includes a hollow recess intowhich the spring 74 extends to maintain proper alignment of the pair.

[0035] The shaft 72 is preferably cylindrical with a central axiscoinciding with the second rotational axis 66 of the correspondingrecess 64. The outer diameter of the shaft 72 is larger than the innerdiameter of opening 68 so that it cannot pass therethrough. The biasingspring 74 biases the shaft 72 to pass through the slot 60 and into therecess portion 64 a arranged in the first housing piece 30 a. In thisbiased position (shown, e.g., in FIG. 6), the shaft 72 intersects theslot 60. However, a key or instrument 76 having a suitably narrow tip 78can be pushed (schematically indicated by an arrow 80) into the opening68 to oppose and overcome the biasing force produced by the spring 74and push the entire shaft 72 into the larger recess portion 64 b of thesecond housing piece 30 b thereby freeing up the gap between the recessportions 64 a, 64 b defined by the slot 60. To facilitate the insertionof the tip 78 into the opening 68, the opening 68 optionally has aportion with a varying diameter shaped as a frustum of a cone asillustrated in FIGS. 2-4 and 6.

[0036] The preferred operation of the illustrated retention assembly 70is as follows. The instrument 76 is inserted through the opening 68 topush (in the direction of arrow 80) the shaft 72 out of the gap definedby the slot 60 and into the recess portion 64 b. The proximate end 52 ofthe cutting tool 22 is inserted along plane 62 into the gap 60 until itcontacts or nearly contacts the tip 78 of the instrument 76. The tip 78is preferably narrower than the shaft 72. Hence, when the tip 78 iswithdrawn, the shaft 72, under the biasing force of the spring 74, willcontact the proximate end 52 of the cutting tool 22 and be preventedfrom passing through the gap defined by slot 60 and entering into therecess portion 64 a. With the tip 78 withdrawn, the proximate end 52 ofthe cutting tool 22 is pushed further into the slot 60 until the opening54 overlaps the shaft 72, at which position the shaft 72 is no longerrestrained by the proximate end 52. Accordingly, under the biasing forceof the spring 74, the shaft 72 is made to pass through the opening 54and into the first recess portion 64 a. In this manner, the cutting tool22 is readily and quickly installed such that the biased shaft 72retains the cutting tool 22 at the periphery 50 of the cutting element20. The cutting tool 22 is however free to rotate about the shaft 72whose axis of symmetry coincides with second rotational axis 66.

[0037] To remove the elongated cutting element 22, the instrument 76 isinserted through the opening 68 to push (in the direction of arrow 80)the shaft 72 out of the gap defined by the slot 60 and into the recessportion 64 b. The elongated cutting element 22 is withdrawn along plane62 from the slot 60 so that the opening 54 is no longer coaxial with thesecond rotational axis 66 and a portion of the proximate end 52 overlapsthe shaft 72. Once again, this overlap is enabled by the tip 78 having asmaller cross-section than the shaft 72. The instrument 76 is thenwithdrawn from the opening 68, at which point the shaft 72 is preventedby the aforementioned overlap from passing through the gap defined byslot 60 and entering into the recess portion 64 a. The cutting tool 22is then completely withdrawn from the slot 60, during which withdrawingthe proximate end 52 unblocks the gap defined by slot 60 so that thebiasing spring 74 pushes the shaft 72 back into the first recess portion64 a. In this manner, the cutting tool 22 is readily and quicklydetached from the cutting element 20.

[0038] It should be appreciated that, although a particular instrument76 is shown for assisting in installing and removing the cutting tools22, a specialized key, wrench or other tool is typically unnecessary.Rather, other commonly available objects having sufficiently narrow andsturdy tips can be used, e.g., the tip of a sharpened pencil or pen, ascrewdriver, scissor tips, the tip of a house key or car key or otherlike key, a simple stick, etc. Preferably, the applied tip is narrowerthan the shaft 72 to permit the proximate end 52 of the cutting tool 22to overlap and block the shaft 72 when the tip is withdrawn.

[0039] In operation, the installed cutting tools 22 are free to rotateabout the second rotational axis 66 except to the extent that thecutting region 56, i.e. the blade portion, impinges upon the supporthousing 30. As the support housing 30 is rotated by an associated driveshaft 26, a centrifugal force directed outwardly from the firstrotational axis 44 develops in the vicinity of the outer edge 50. Underthe influence of the centrifugal force, the cutting region 56 will tendto move radially outward away from the first rotational axis 44. Becausethe cutting tools 22 are free to rotate about their respective secondrotational axes 66, they rotate so that their cutting regions 56 aresubstantially aligned with the outward direction of the centrifugalforce thereby provide an effective cutting edge.

[0040] As the support housing 30 rotates and the cutting region 56orients outwardly, the cutting tool 22 is in position to cut or trimunwanted weeds, overgrown grasses, and other vegetation or plants thatimpinge thereupon. However, if the cutting region 56 strikes a rock,tree trunk, or other hard and/or immobile object, which does not yieldthereto, the cutting tool 22 pivots about the second rotational axis 66responsive to the unyielding force thereby avoiding a substantial impactwhich could potentially damage the cutting tool 22 and/or the unyieldingobject struck.

[0041] Because the elongated cutting elements 22 are easily replaced,durability becomes less of a factor, and so there is greater flexibilityin the selection of suitable materials. The material can be selected tobalance blade durability with safety and ease of rotation. In onepreferred embodiment, a molded nylon material is used to manufactureboth the cutting tools 22 and the support housing 30. However, it isalso contemplated to use steel or other metals, plastics, hard rubber,or like materials as desired depending on the application.

[0042] In a suitable method for assembling the rotary cutting element20, the springs 74 and the shafts 72 of the retention assemblies 70 areeach inserted into their respective recess portions 64 b of the secondhousing portion 30 b. The first housing portion 30 a is then matinglyplaced onto the second housing portion 30 b and fastened thereto by oneor more screws, bolt/nut combinations, clamps, adhesives, or the like.The cutting tools 22 are then installed as previously described.Alternatively, for the initial assembly the cutting tools 22 can beinstalled prior to placement of the first housing portion 30 a.

[0043] It is to be appreciated that the present invention is not limitedto the power trimmer 10 shown in FIG. 1, but rather finds application inmany types of horticultural and/or lawn care equipment which employrotary cutting elements or devices, be it hand-operated, power-driven,or otherwise. For example, it will find application in other types ofvegetation cutting and trimming applications, in soil tilingapplications, as well as in other non-horticultural related fields thatemploy similar rotary cutting elements. Optionally, a lawn edger orrototiller may employ the rotary cutting device 20 in a verticalorientation with appropriately shaped and durable cutting tools 22. Insuch an embodiment, however, it may be desired to not have the cuttingtools 22 pivot about their respective axes 66. Accordingly, the shape ofthe opening 54, recess 64 and shaft 72 may be square or otherwisesuitably keyed so maintain the cutting tools 22 at desired rotationallyfix orientations with respect to the axes 66. Alternately, rotation ofthe cutting tools 22 may be thwarted by employing a plurality ofconnection points for each tool 22, or the slot 60 and proximate ends 52of the cutting tools 22 can be appropriately mated or keyed to preventeach tool's rotation.

[0044] Furthermore, the size of the cutting element 20 and/or cuttingtools 22 may selected as desired for particular applications. Forexample, with reference to FIG. 7, a push- or power-propelled lawn mower100 includes a chassis 102 supported by and maneuverable on wheels 104.An driver 24, for example a combustion engine, electric motor orotherwise, is supported by the chassis 102 and selectively drives adrive shaft 26 which connects to and drives the rotating cutting element20 which includes one or more cutting tools 22 that rotate aboutresponsive to a rotation of the cutting element 20 by the drive shaft26.

[0045] The lawn mower 100 further includes a handle 114 terminating in agrip 16 for operation and manipulation of the lawn mower 100.Preferably, the drive 24 effects rotation of the rotating cuttingelement 20 responsive to a user's manipulation of an operational control28. The control 28 is preferably an engagement control which promotessafety by being biased to a disengaged position so as to ensure that thecutting element 20 does not rotate without deliberate action tomanipulate the control 28. Accordingly, under normal operation, when thelawn mower 100 is left unattended the rotary cutting device 20 will notrotate. However, it is also contemplated to omit the control 28 and havethe rotating cutting element 20 continuously operate responsive to thedrive 24 running.

[0046] In a suitable embodiment, the lawn mower 100 is propelled aboutthe ground manually, i.e., an associated user pushes the lawn mower 100via the grip 16 on the handle 114. In another suitable embodiment, thedrive 24 propels the lawn mower 100 by driving selected wheels 104,e.g., the rear wheels, via a mechanical or other linkage 120. Thepropelling is preferably responsive to the user operating a switch 122which effects engagement of the power-propelling and/or selects a speedtherefor. With either push or power propulsion, the associated userpreferably steers using the grip 16 on the handle 114.

[0047] As shown, the lawn mower 100 is operated by a user who walksbehind the lawn mower. However, a riding lawn mower or a mower or brushchopper which is attached to a tractor is also contemplated.

[0048] The invention has been described with reference to the preferredembodiments. Obviously, modifications and alterations will occur toothers upon reading and understanding the preceding detaileddescription. It is intended that the invention be construed as includingall such modifications and alterations insofar as they come within thescope of the appended claims or the equivalents thereof.

What is claimed is:
 1. A rotary cutting device comprising: a base, saidbase including: a coupling region adapted for connection of the basewith an associated drive that rotates the base; a slot at a periphery ofthe base; and, a hollow shaft in communication with the slot; aretaining member arranged in the hollow shaft, said retaining memberbeing movable between a first position wherein the retaining memberintersects the slot and a second position wherein the retaining memberdoes not intersect the slot; and, a cutting tool including a proximateend and a cutting region extending therefrom, said proximate endarranged to be received in the slot and having an opening arranged toreceive the retaining member therethrough when the retaining member isin the first position.
 2. The rotary cutting device of claim 1, furtherincluding: a spring arranged to bias the retaining member into the firstposition.
 3. The rotary cutting device of claim 2, wherein the baseincludes an opening communicating with the hollow shaft to admit anassociated instrument into the hollow shaft for selectively sliding theretaining member against the biasing of the spring into the secondposition.
 4. The rotary cutting device of claim 1, wherein the retainingmember is movable by sliding translation between the first and secondpositions.
 5. The rotary cutting device of claim 1, wherein the hollowshaft is defined by a first recessed portion and a second recessedportion aligned on opposing sides of the slot such that the hollow shaftintersects the slot at an orientation substantially normal to a planedefined by the slot.
 6. The rotary cutting device of claim 5, whereinthe base is constructed of a first piece and a second piece connectedtogether such that they cooperatively define the slot therebetween. 7.The rotary cutting device of claim 6, wherein the first piece includesthe first recessed portion and the second piece includes the secondrecessed portion.
 8. The rotary cutting device of claim 1, wherein thebase includes a plurality of the hollow shafts, said plurality of hollowshafts containing a corresponding plurality of the retaining memberssuch that a plurality of the cutting tools are selectively securable tothe base.
 9. A horticultural apparatus comprising: a drive; a baseoperatively connected to the drive for selective rotation thereby, saidbase having a peripheral opening; a cutting tool having a proximate endwhich is received into the peripheral opening; and, a retaining memberarranged in the base, said retaining member being movable between afirst position in which the retaining member is engaged with the cuttingtool to secure the cutting tool to the base and a second position inwhich the retaining member is disengaged from the cutting tool torelease the cutting tool from the base.
 10. The horticultural apparatusof claim 9, wherein said horticultural apparatus is selected from apower trimmer, a mower, an edger, a brush chopper or a rototiller. 11.The horticultural apparatus of claim 9, further comprising: a springwhich biases the retaining member to the first position.
 12. Thehorticultural apparatus of claim 9, wherein the retaining member ismovable by sliding translation between the first and second positions.13. The horticultural apparatus of claim 9, wherein the base includes anaccess opening that admits an instrument for selectively moving theretaining member into the second position.
 14. The horticulturalapparatus of claim 13, wherein the access opening is narrower than adimension of the retaining member.
 15. The cutting apparatus as setforth in claim 13, wherein the access opening includes a frustum shapedregion.
 16. The horticultural apparatus of claim 9, wherein thehorticultural apparatus includes a plurality of the retaining memberssuch that a plurality of the cutting tools are selectively securable tothe base.
 17. A rotary cutting element to which a cutting tool isselectively secured, said rotary cutting element comprising: a centrallyarranged fastening region adapted to operatively connect with a drivethat rotates the rotary cutting element; a periphery having a slotadapted to receive an end the cutting tool; a recess in communicationwith the slot; a retaining member arranged in the recess, said retainingmember slidable between a first position wherein the retaining memberintersect the slot and a second position wherein the retaining memberdoes not intersect the slot; and, a spring which biases the retainingmember toward the first position.
 18. The rotary cutting element ofclaim 17, further comprising: an access port that admits an instrumentfor selectively moving the retaining member into the second position.19. The rotary cutting element of claim 17, wherein the centrallyarranged fastening region includes: an opening, said opening having afirst diameter.
 20. The rotary cutting element of claim 19, wherein thecentrally arranged fastening region further includes: an annular recessdisposed about the opening, said annular recess adapted to receive awasher having a selected inner diameter lest than or equal to the firstdiameter.